1. Field of the Invention
The present invention relates to a movable member control device for stopping a movable member at a position corresponding to an analog signal.
2. Description of the Prior Art
In order to move a movable member and stop it at a position corresponding to an analog signal, it is necessary that the instantaneous position of the movable member is converted to a signal that can be compared with the analog signal. A conventional device for this purpose includes a slider contact slidable on a resistor band or strip in a linked relationship with the movable member whereupon a signal representative of the position of the movable member is derived through the slider contact. However, such a conventional device is subject to the following disadvantages. As the slider contact is adapted to slide on a resistor strip, the latter is subject to wear which changes the resistance and accordingly the relationship between the position of the movable member and the output from the slider contact. In short, the conventional device has poor durability. Additionally, if a servomechanism is employed to continuously drive the movable member, a target position signal representing a target position at which the movable member is to be stopped is compared with a continuously changing signal derived from the slider contact whereby hunting is likely to occur, wherein the movable member oscillates about the target position.